Mixture which can be thermally hardened and hardened by actinic radiation and use thereof

ABSTRACT

A mixture and method for preparing a composition curable thermally and with actinic radiation comprising a binder free from carbon-carbon double bonds activatable with actinic radiation, at least one blocked or unblocked polyisocyanate having at least one soft, flexibilizing segment, and at least one unsaturated polyfunctional urethane that is free from isocyanate-reactive functional groups and contains on average per molecule more than four carbon-carbon double bonds activatable with actinic radiation and at least one hardening segment.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Application of Patent ApplicationPCT/EP02/02838 filed on 14 Mar. 2002, which claims priority to DE 101 15604.9, filed on 29 Mar. 2001.

The present invention relates to a novel mixture curable thermally andwith actinic radiation. The present invention also relates to the use ofthe novel mixture curable thermally and with actinic radiation as acoating material, adhesive or sealing compound.

Actinic radiation here and below means electromagnetic radiation such asnear infrared, visible light, UV radiation or X-rays, especially UVradiation, and corpuscular radiation such as electron beams.

Combined curing by heat and actinic radiation is referred to by those inthe art as dual cure. Accordingly, here and below, the novel mixtures,coating materials, adhesives and sealing compounds in question arereferred to as dual-cure mixtures, coating materials, adhesives andsealing compounds.

Thermally curable mixtures comprising

-   -   binder mixtures which are free from (meth)acryloyl groups and        comprise (meth)acrylate copolymers having low glass transition        temperatures Tg and (meth)acrylate copolymers having high glass        transition temperatures Tg, and    -   unblocked polyisocyanates        are known from the European patent EP 0 853 694 B1. The        thermally curable mixtures are suitable as clearcoat materials        for automotive OEM finishing and give clearcoats having high        acid resistance, an excellent topcoat appearance, and good        resistance to condensation. They cannot be cured with actinic        radiation. Furthermore, the European patent application does not        indicate how the profile of properties of the known thermally        curable mixtures might be adjusted via the structure of the        blocked polyisocyanates. Furthermore, the (meth)acrylate        copolymers with low glass transition temperatures Tg must not        contain styrene or any styrene derivatives, thereby greatly        restricting the variation of the material composition of the        (meth)acrylate copolymers in question.

Dual-cure mixtures are known from the German patent application DE 19818 735 A1. The dual-cure mixtures necessarily include constituents, suchas (meth)acrylate copolymers, which besides isocyanate-reactivefunctional groups mandatorily contain (meth)acryloyl groups, andconstituents, such as (meth)acrylate copolymers, for example, whichbesides complementary free isocyanate groups likewise mandatorilycontain (meth)acryloyl groups. Furthermore, they may comprise(meth)acrylate copolymers which are free from (meth)acryloyl groups butcontain isocyanate-reactive groups. Over and above this, the Germanpatent application describes a host of alternatives to these components,which are all said to be of equal effect. For example, instead of the(meth)acrylate copolymers which besides isocyanate-reactive functionalgroups mandatorily contain (meth)acryloyl groups it is possible to usethe analogous urethane (meth)acrylates. Moreover, the glass transitiontemperatures, Tg, which the (meth)acryloyl-free (meth)acrylatecopolymers are to have are not stated.

It is indeed stated that the known dual-cure coating materials givecoatings having very good chemical, gasoline and solvent resistance,high scratch resistance, and good and rapid sandability, and are said inthis respect to satisfy the requirements imposed on a multicoat systemin the field of automotive finishing, especially automotive refinish.Furthermore, the coatings are said to be free from cracks and to exhibitgood adhesion to the substrate. Overall, they are said to show aflawless visual appearance. But as to how this profile of properties canbe optimized and adjusted in detail, and as to which of the virtuallyinnumerable alternatives, which may be inferred from a plurality oflists, are the ones which function best, neither the description nor anyexample gives specifics.

The German patent application DE 199 20 799 A1 discloses dual-curemixtures used to produce seals for SMCs (Sheet Molded Compounds) andBMCs (Bulk Molded Compounds). The seals suppress the formation ofmicrobubbles and have a smooth surface free from structures such asorange peel and requiring no aftertreatment; instead, the surfaces canbe overcoated easily and safely without any subsequent problems ofintercoat adhesion.

The known dual-cure mixture necessarily includes at least oneconstituent containing at least two functional groups which serve forcrosslinking with actinic radiation and at least one functional groupwhich, together with a complementary functional group in anotherconstituent, is able to undergo thermal crosslinking reactions, such as,for example, the isocyanato acrylates known from European patentapplication EP 0 928 800 A1.

The mixture may comprise, inter alia, at least one urethane(meth)acrylate which is free from isocyanate-reactive functional groups.Furthermore, it may comprise constituents, such as (meth)acrylatecopolymers, which contain (meth)acryloyl groups and also, if desired,reactive functional groups for the thermal crosslinking.

Furthermore, the dual-cure mixture may also include thermally curable(meth)acrylate copolymers, to which, however, numerous alternatives areindicated. Moreover, no closer characterization is given of thethermally curable (meth)acrylate copolymers with regard alternatively totheir composition, their glass transition temperature Tg, or the amountof reactive functional groups for thermal crosslinking they contain.

Additionally, the dual-cure mixture may comprise blockedpolyisocyanates. There is, however, no reference to an intention thatblocked or unblocked polyisocyanates which contain at least one soft,flexibilizing segment as a molecular building block should be used withpreference.

A comparable dual-cure coating material is known from the German patentapplication DE 199 20 801 A1. As far as the thermally curable(meth)acrylate copolymers are concerned, all that is stated is thattheir amount should generally not exceed 40% by weight, based on thecoating material. The known dual-cure coating material is used toproduce multicoat clearcoat systems which are highly scratch-resistant,weathering-stable, yellowing-free, hard, flexible, and free of surfacedefects, on all substrates and which also exhibit a high level ofadhesion within the clearcoat systems and may be produced in the highcoat thickness required for an outstanding overall visual appearance.For this purpose, a film of the dual-cure coating material is overcoatedwith a further film of the dual-cure coating material which containsnanoparticles, after which the two films are cured together. Thisprocess, however, is comparatively complex.

The international patent application WO 98/40170 discloses a dual-cureclearcoat material for a wet-on-wet technique in which a film of abasecoat material is overcoated with a clearcoat material and then theresulting clearcoat film is exposed to actinic radiation before the twofilms are baked together. The clearcoat material contains, based on itssolids content, from 50 to 98% by weight of a system A) which is curablethermally by addition and/or condensation reactions, and issubstantially free from free-radically polymerizable double bonds andsubstantially free from groups reactive in other ways withfree-radically polymerizable double bonds of the system B), and from 2to 50% by weight of a system B) which can be cured by free-radicalpolymerization of olefinic double bonds on exposure to actinicradiation.

The system A) preferably comprises a hydroxy-functional acrylic binderwhose glass transition temperature, however, is not specified.Accordingly, the skilled worker is unable to derive anything from theinternational patent application regarding the significance of thisparameter for the adjustment of the hardness and of the scratchresistance and other important performance properties, such as thechemical resistance, of clearcoats, especially in the shadow zones ofthree-dimensional substrates of complex shape.

The system B) which can be cured by free-radical polymerization ofolefinic double bonds may comprise a hexafunctional aliphatic urethaneacrylate with a theoretical molar weight of 800 or 1 000.

The known dual-cure clearcoat material may be a one-component system ora two-component or multicomponent system. It is said to give a clearcoathaving an outstanding visual/esthetic appearance. During its production,there is said to be no running from vertical surfaces. The clearcoat issaid to exhibit reduced susceptibility to chemicals and scratching,especially to acid and wash scratches.

In order for clearcoats to be able to be used in the esthetically andtechnologically highly demanding field of automotive finishing, theymust be hard and scratch resistant. The scratch resistance may resultfrom the flexibility of the clearcoats, which has the effect thatmicroscratches, as brought about, for example, by the brushes in carwash installations, close up again. Alternatively, the scratchresistance may result from the resilience of the clearcoat, whichderives from a high storage modulus. This correlates directly withcrosslinking density of the coating.

Although the dual-cure mixtures known to date are able to eliminate thisproblem to a certain degree, there is to date no entirely satisfactory,simple solution. In particular, it is unknown how and in what amountsthe conventional constituents of dual-cure mixtures of the prior arthave to be combined specifically with one another in order to give hardand scratch-resistant clearcoats even in the shadow zones ofthree-dimensional substrates of complex shape, where the clearcoats arealso intended to exhibit high chemical resistance, weathering stability,condensation resistance, and intercoat adhesion.

It is an object of the present invention to provide a novel mixturecurable thermally and with actinic radiation which no longer has thedisadvantages of the prior art. The dual-cure mixture should be easy toprepare and should be suitable for use as a coating material, adhesiveor sealing compound. The dual-cure coating materials, adhesives andsealing compounds should be simple to apply and should give coatings,adhesives and seals having a very good profile of performanceproperties. Where the dual-cure coating materials are used as dual-curecoat materials, they should give hard, flexible, scratch-resistant,chemical-resistant, acid-resistant, water-resistant andweathering-stable clearcoats having an outstanding overall visualappearance and excellent intercoat adhesion. Moreover, they shouldexhibit good to very good adhesion to customary and known automotiverefinishes and to automotive production-line repair finishes, where, asis known, ready-coated bodies are overcoated once again in total withthe OEM finishes.

Accordingly, the invention provides the novel mixture curable thermallyand with actinic radiation, comprising

-   (A) a binder free from carbon-carbon double bonds activatable with    actinic radiation, comprising at least one (meth)acrylate copolymer    containing on average per molecule at least one isocyanate-reactive    functional group and having a glass transition temperature Tg of    from −40 to +80° C.,-   (B) at least one blocked and/or unblocked polyisocyanate having at    least one soft, flexibilizing segment, which as a constituent of    three-dimensional polymeric networks lowers their glass transition    temperature Tg, and-   (C) at least one unsaturated polyfunctional urethane which is free    from isocyanate-reactive functional groups and contains on average    per molecule more than four carbon-carbon double bonds activatable    with actinic radiation and at least one hardening segment, the    hardening segment as a constituent of three-dimensional polymer    networks increasing their glass transition temperature Tg.

In the text below, the novel mixture curable thermally and with actinicradiation is referred to as the “dual-cure mixture of the invention”.

Further subject matter of the invention will emerge from thedescription.

In the light of the prior art, it was surprising and unforeseeable forthe skilled worker that the object on which the present invention isbased could be achieved with the aid of the dual-cure mixture of theinvention. A particular surprise was that the dual-cure mixture of theinvention, as a one-component system containing blocked polyisocyanates(B), was stable on storage even under extreme climatic conditions orsevere climatic fluctuations. The dual-cure mixture could be used bothas a one-component system or as a two-component or multicomponent systemin the form of a coating material, adhesive or sealing compound, theextremely broad applicability being an even greater surprise. Thedual-cure coating materials, adhesives and sealing compounds were easyto prepare and apply and gave coatings, adhesive films and seals havinga very good profile of performance properties. When the dual-curecoating materials were used as dual-cure clearcoat materials, they gavehard, flexible, scratch-resistant, chemical-resistant, acid-resistant,water-resistant and weathering-stable clearcoats having an outstandingoverall visual appearance and outstanding intercoat adhesion.Furthermore, even in the unsanded state, they have good to very goodadhesion to customary finishes and automotive refinishes.

The first key constituent of the novel dual-cure mixture is a binder (A)which is free of carbon-carbon double bonds activatable with actinicradiation. In the context of the present invention, “free ofcarbon-carbon double bonds” means that the binders (A) in questioncontain no, or only technically occasioned traces of, such double bonds.

The binder (A) contains at least one, preferably at least two,(meth)acrylate copolymer(s) (A) containing on average per molecule atleast one, preferably at least two, with particular preference at leastthree, and in particular at least four isocyanate-reactive groups.

Examples of suitable isocyanate-reactive functional groups, hereinbelow,are thiol, hydroxyl and primary and secondary amino groups, especiallyhydroxyl groups.

The (meth)acrylate copolymer (A) or the mixture of at least two(meth)acrylate copolymers (A) has a glass transition temperature Tg offrom −40 to +80° C.

Where only one (meth)acrylate copolymer (A) is used, it may have a lowor a high glass transition temperature Tg. The (meth)acrylate copolymer(A) preferably has a low glass transition temperature Tg, preferablybelow room temperature, in particular below 0° C.

In one preferred embodiment the binder (A) comprises at least one,especially one, (meth)acrylate copolymer (A1) and at least one,especially one, (meth)acrylate copolymer (A2), or the binder consists ofthese (meth)acrylate copolymers (A1) and (A2).

The (meth)acrylate copolymer (A1) contains on average per molecule atleast one, preferably at least two, with particular preference at leastthree, and in particular at least four isocyanate-reactive functionalgroups and has a glass transition temperature Tg below room temperature,preferably below 0, more preferably below −5, with particular preferencebelow −10, with very particular preference below −15, and in particularbelow −20° C.

The (meth)acrylate copolymer (A2) contains on average per molecule atleast one, preferably at least two, with particular preference at leastthree, and in particular at least four isocyanate-reactive functionalgroups and has a glass transition temperature Tg above room temperature,preferably above 30, more preferably above 32, very preferably above 35,with particular preference above 40, with very particular preferenceabove 42, and in particular above 45° C.

Examples of suitable isocyanate-reactive groups for use in the(meth)acrylate copolymers (A1) and (A2) are thiol, hydroxyl and primaryand secondary amino groups. The (meth)acrylate copolymers (A1) and (A2)may contain different or identical isocyanate-reactive groups, orcombinations of isocyanate-reactive groups, with the number ofisocyanate-reactive groups in the (meth)acrylate copolymers (A1), on theone hand, and in the (meth)acrylate copolymers (A2), on the other hand,being identical or different. For example, the (meth)acrylate copolymers(A1) may contain hydroxyl groups and the (meth)acrylate copolymers (A2)may contain secondary and/or primary amino groups. Numerous furtherpermutations are conceivable here, and are easy for the skilled workerto infer, so that there is no need to go into this in detail here.

Preferably, hydroxyl groups are used.

The hydroxyl content of the (meth)acrylate copolymers (A1) and (A2) mayvary widely. The lower limit is a result of the proviso that there mustbe at least one hydroxyl group in the (meth)acrylate copolymers (A1) and(A2). The hydroxyl number is preferably from 50 to 300, more preferablyfrom 80 to 250, very preferably from 100 to 220, with particularpreference from 120 to 200, with very particular preference from 140 to190, and in particular from 150 to 185.

The (meth)acrylate copolymers (A1) and (A2) have an acid number of from0 to 70, preferably from 3 to 65, more preferably from 5 to 60, withparticular preference from 7 to 55, with very particular preference from10 to 50, and in particular from 12 to 45 mg KOH/g. It is possible forone of the (meth)acrylate copolymers, (A1) or (A2), to have an acidnumber of 0 mg KOH/g, while the other (meth)acrylate copolymer, (A2) or(A1), has an acid number >0 mg KOH/g. Preferably, the (meth)acrylatecopolymers (A1) and (A2) have the same, or approximately the same, acidnumber.

The weight ratio of (meth)acrylate copolymer (A1) to (meth)acrylatecopolymer (A2) may vary widely from one binder (A) to another.Preferably, the weight ratio of (A1) to (A2) is from 1:10 to 10:1, morepreferably from 1:8 to 8:1, with particular preference from 1:6 to 6:1,with very particular preference from 1:4 to 4:1, and in particular from1:2 to 2:1.

It is a particular advantage of the mixture of the invention that theabove-described (meth)acrylate copolymers (A1) and (A-2) may also beused individually as binder (A) without any risk of this lessening theadvantageous technical effect aimed at in accordance with the invention.Indeed, it is a further, very particular advantage of the mixture of theinvention that any, possibly unwanted change in the profile ofproperties which may be induced by the choice of the binder (A) caneasily be compensated, or even overcompensated, by appropriate selectionof the blocked or unblocked polyisocyanates (B) described below and/orof the polyfunctional unsaturated urethanes (C) described below.

The above-described (meth)acrylate copolymers (A), including the(meth)acrylate copolymers (A1) and (A2), are prepared by free-radicalcopolymerization of at least two, preferably at least three and inparticular at least four different olefinically unsaturated monomers(a).

One of the monomers (a) is an olefinically unsaturated monomer (a1) bymeans of which the isocyanate-reactive functional groups are introducedinto the (meth)acrylate copolymers (A). At least one of the othermonomers (a) substantially comprises olefinically unsaturated monomers(a2) containing no isocyanate-reactive functional groups. These monomers(a2) may be free of reactive functional groups or may contain reactivefunctional groups which are able to undergo thermal crosslinkingreactions with other, complementary reactive functional groups, with theexception of isocyanate groups.

Examples of suitable olefinically unsaturated monomers (a1) are

-   -   hydroxyalkyl esters of alpha,beta-olefinically unsaturated        carboxylic acids, such as hydroxyalkyl esters of acrylic acid,        methacrylic acid and ethacrylic acid in which the hydroxyalkyl        group contains up to 20 carbon atoms, such as 2-hydroxyethyl,        2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl        acrylate, methacrylate or ethacrylate;        1,4-bis(hydroxy-methyl)cyclohexane,        octahydro-4,7-methano-1-H-indenedimethanol or methylpropanediol        mono-acrylate, monomethacrylate, monoethacrylate or        monocrotonate; or reaction products of cyclic esters, such as        epsilon-caprolactone, and these hydroxyalkyl esters;    -   olefinically unsaturated alcohols such as allyl alcohol;    -   allyl ethers of polyols, such as trimethylolpropane monoallyl        ether or penta-erythritol monoallyl, diallyl or triallyl ether.        The monomers (a1) of higher functionality are generally used        only in minor amounts. In the context of the present invention,        minor amounts of higher-functional monomers here means those        amounts which do not lead to crosslinking or gelling of the        (meth)acrylate copolymers (A1) and/or (A2), unless the        (meth)acrylate copolymers (A1) and/or (A2) are intended to be in        the form of crosslinked microgel particles;    -   reaction products of alpha,beta-olefinically unsaturated        carboxylic acids with glycidyl esters of an alpha-branched        monocarboxylic acid having from 5 to 18 carbon atoms in the        molecule. The reaction of acrylic or methacrylic acid with the        glycidyl ester of a carboxylic acid having a tertiary alpha        carbon atom may take place before, during or after the        polymerization reaction. Preference is given to using, as        component (a1), the reaction product of acrylic and/or        methacrylic acid with the glycidyl ester of Versatic® acid. This        glycidyl ester is available commercially under the name Cardura®        E10. For further details, attention is drawn to Römpp Lexikon        Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, N.Y.,        1998, pages 605 and 606;    -   allylamine and crotylamine;    -   aminoalkyl esters of alpha,beta-olefinically unsaturated        carboxylic acids, such as aminoethyl acrylate, aminoethyl        methacrylate or N-methylaminoethyl acrylate;    -   formaldehyde adducts of aminoalkyl esters of        alpha,beta-olefinically unsaturated carboxylic acids and of        alpha,beta-unsaturated carboxamides, such as N-methylol- and        N,N-dimethylol-aminoethyl acrylate, -aminoethyl methacrylate,        -acrylamide and -methacrylamide; and also    -   olefinically unsaturated monomers containing acryloxysilane        groups and hydroxyl groups, preparable by reacting        hydroxy-functional silanes with epichlorohydrin and then        reacting the intermediate with an alpha,beta-olefinically        unsaturated carboxylic acid, especially acrylic acid and        methacrylic acid, or hydroxyalkyl esters thereof.

Of these monomers (a1), the hydroxyalkyl esters, especially the2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl,4-hydroxybutyl esters of acrylic acid and methacrylic acid are ofadvantage and are therefore used with particular preference.

Examples of suitable olefinically unsaturated monomers (a2) are

-   -   alpha,beta-olefinically unsaturated carboxylic acids, such as        acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid,        maleic acid, fumaric acid, itaconic acid,        mono(meth)acryloyloxyethyl maleate, mono(meth)acryloyloxyethyl        succinate and mono(meth)acryloyloxyethyl phthalate, and also        vinylbenzoic acid (all isomers) and alpha-methylvinylbenzoic        acid (all isomers), especially acrylic acid and/or methacrylic        acid;    -   alkyl and cycloalkyl esters of alpha,beta-olefinically        unsaturated carboxylic acids, phosphonic acids and sulfonic        acids, such as (meth)acrylic, crotonic, ethacrylic,        vinylphosphonic or vinylsulfonic alkyl or cycloalkyl esters        having up to 20 carbon atoms in the alkyl radical, especially        methyl, ethyl, propyl, n-butyl, sec-butyl, tert-butyl, hexyl,        ethylhexyl, stearyl and lauryl acrylate, methacrylate,        crotonate, ethacrylate or vinylphosphonate or vinylsulfonate;        cycloaliphatic (meth)acrylic, crotonic, ethacrylic,        vinylphosphonic or vinylsulfonic esters, especially cyclohexyl,        isobornyl, dicyclopentadienyl,        octahydro-4,7-methano-1-H-indenemethanol or tert-butylcyclohexyl        (meth)acrylate, crotonate, ethacrylate, vinylphosphonate or        vinylsulfonate. These may contain, in minor amounts,        higher-functional (meth)acrylic, crotonic or ethacrylic alkyl or        cycloalkyl esters such as ethylene glycol, propylene glycol,        diethlylene glycol, dipropylene glycol, butylene glycol,        pentane-1,5-diol, hexane-1,6-diol,        octahydro-4,7-methano-1H-indenedimethanol or cyclohexane-1,2-,        -1,3- or -1,4-diol di(meth)acrylate; trimethylolpropane        tri(meth)acrylate; or pentaerythritol tetra(meth)acrylate and        also the analogous ethacrylates or crotonates. In the context of        the present invention, minor amounts of higher-functional        monomers (a2) means amounts which do not lead to crosslinking or        gelling of the (meth)acrylate copolymers (A), unless the        (meth)acrylate copolymers (A) are to be in the form of        crosslinked microgel particles;    -   allyl ethers of alcohols, such as allyl ethyl ether, allyl        propyl ether or allyl n-butyl ether, or of polyols, such as        ethylene glycol diallyl ether, trimethylolpropane triallyl ether        or pentaerythritol tetraallyl ether. Regarding the        higher-functional allyl ethers (a2), the comments made above        apply analogously;    -   olefins such as ethylene, propylene, but-1-ene, pent-1-ene,        hex-1-ene, cyclohexene, cyclopentene, norbornene, butadiene,        isoprene, cyclopentadiene and/or dicyclopentadiene;    -   amides of alpha,beta-olefinically unsaturated carboxylic acids,        such as (meth)acrylamide, N-methyl-, N,N-dimethyl-, N-ethyl-,        N,N-diethyl-, N-propyl-, N,N,-dipropyl-, N-butyl-, N,N-dibutyl-        and/or N,N-cyclohexyl-methyl-(meth)acrylamide;    -   monomers containing epoxide groups, such as the glycidyl ester        of acrylic acid, methacrylic acid, ethacrylic acid, crotonic        acid, maleic acid, fumaric acid and/or itaconic acid;    -   vinylaromatic hydrocarbons, such as styrene,        alpha-alkylstyrenes, especially alpha-methyl-styrene and        vinyltoluene, and diphenylethylene or stilbene;    -   nitriles, such as acrylonitrile and/or methacrylonitrile;    -   vinyl compounds such as vinyl chloride, vinyl fluoride,        vinylidene dichloride, vinylidene difluoride;        N-vinylpyrrolidone; vinyl ethers such as ethyl vinyl ether,        n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl        ether, isobutyl vinyl ether and/or vinyl cyclohexyl ether; vinyl        esters such as vinyl acetate, vinyl propionate, vinyl butyrate,        vinyl pivalate, vinyl esters of Versatic® acids, which are sold        under the brand name VeoVa® by Deutsche Shell Chemie (for        further details, attention is drawn to Römpp Lexikon Lacke und        Druckfarben, Georg Thieme Verlag, Stuttgart, N.Y., 1998, page        598 and also pages 605 and 606) and/or the vinyl ester of        2-methyl-2-ethylheptanoic acid; and    -   polysiloxane macromonomers which have a number average molecular        weight Mn of from 1 000 to 40 000, preferably from 2 000 to 20        000, with particular preference from 2 500 to 10 000, and in        particular from 3 000 to 7 000, and contain on average from 0.5        to 2.5, preferably from 0.5 to 1.5, ethylenically unsaturated        double bonds per molecule, as described in DE 38 07 571 A1 on        pages 5 to 7, in DE 37 06 095 A1 in columns 3 to 7, in EP 0 358        153 B1 on pages 3 to 6, in U.S. Pat. No. 4,754,014 A1 in columns        5 to 9, in DE 44 21 823 A1 or in the international patent        application WO 92/22615 on page 12 line 18 to page 18 line 10.

It is generally the case that monomers (a1) and (a2) are selected sothat the profile of properties of the (meth)acrylate copolymers (A) isdetermined essentially by the above-described (meth)acrylate monomers(a1) and (a2), with the monomers (a1) and/or (a2) originating from othermonomer classes varying this profile of properties in an advantageouslybroad and targeted manner. The monomers (a) are selected so as to givethe above-described glass transition temperatures Tg and also thehydroxyl numbers and acid numbers.

The skilled worker may select the monomers (a) with the aid of thefollowing formula of Fox, by means of which the glass transitiontemperatures of polyacrylate resins may be calculated approximately:

$\begin{matrix}{{{1/{Tg}} = {\sum\limits_{n = 1}^{n = x}{{Wn}/{Tg}_{n}}}};} & \; & {{\sum\limits_{n}W_{n}} = 1}\end{matrix}$

-   Tg=glass transition temperature of the (meth)acrylate copolymer-   W_(n)=weight fraction of the nth monomer-   Tg_(n)=glass transition temperature of the homopolymer of the nth    monomer-   x=number of different monomers

Viewed in terms of its method, the copolymerization has no specialfeatures, but instead takes place with the aid of the methods andapparatus as commonly employed for free-radical copolymerization insolution or in bulk in the presence of a free-radical initiator.

Examples of free-radical initiators which may be used are as follows:dialkyl peroxides, such as di-tert-butyl peroxide or dicumyl peroxide;hydroperoxides, such as cumene hydroperoxide or tert-butylhydroperoxide; peresters, such as tert-butyl perbenzoate, tert-butylperpivalate, tert-butyl per-3,5,5-trimethylhexanoate or tert-butylper-2-ethylhexanoate; peroxodicarbonates; potassium, sodium or ammoniumperoxodisulfate; azo initiators, examples being azo dinitriles such asazobisisobutyronitrile; C—C cleaving initiators such as benzpinacolsilyl ethers; or a combination of a nonoxidizing initiator with hydrogenperoxide. It is also possible to use combinations of the above-describedinitiators. Further examples of suitable initiators are described in theGerman patent application DE-A-196 28 142 on page 3 line 49 to page 4line 6.

In the organic solutions or in bulk, the monomers (a) are thencopolymerized with the aid of the aforementioned free-radical initiatorsat reaction temperatures which preferably lie below the lowestdecomposition temperature of the respective monomers (a) employed.

Examples of organic solvents are described in “Paints, Coatings andSolvents”, Dieter Stoye and Werner Freitag (editors), Wiley-VCH, 2ndedition, 1998, pages 327 to 349.

It is preferred to commence the addition of initiator at a certain time,generally from about 1 to 15 minutes, before adding the monomers.Preference is further given to a process in which the addition ofinitiator is commenced at the same point in time as the addition of themonomers and ended about half an hour after the addition of the monomershas ended. The initiator is preferably added in a constant amount perunit time. Following the end of the addition of initiator, the reactionmixture is held at polymerization temperature until (generally from 1 to6 hours) all of the monomers (a) employed have undergone substantiallycomplete reaction. “Substantially complete reaction” is intended to meanthat preferably 100% by weight of the monomers used are reacted but thatit is also possible for a small residual monomer content of not morethan up to about 0.5% by weight, based on the weight of the reactionmixture, to remain unreacted.

Suitable reactors for the copolymerization include the customary andknown stirred tanks, stirred tank cascades, tube reactors, loop reactorsor Taylor reactors, as described for example in the patent DE 1 071 241B1, in the patent applications EP 0 498 583 A1 and DE 198 28 742 A1, orin the article by K. Kataoka in Chemical Engineering Science, Volume 50,Number 9, 1995, pages 1409 to 1416.

With regard to the molecular weight distribution, the (meth)acrylatecopolymer (A) is not subject to any restrictions whatsoever.Advantageously, however, the copolymerization is carried out so as togive a molecular weight distribution Mw/Mn, measured by means of gelpermeation chromatography using polystyrene as standard, of ≦4,preferably ≦2, and in particular ≦1.5, and also, in certain cases, ≦1.3.

The amount of the above-described binders (A) in the dual-cure mixtureof the invention may vary widely and depends on the requirements of thecase in hand. A key factor here is the functionality of the binder (A)with regard to thermal crosslinking, i.e., the number ofisocyanate-reactive groups present in the binder mixture (A). Theskilled worker will therefore be able to determine the amount with easeon the basis of his or her general knowledge in the art, with the aid ifdesired of simple rangefinding experiments. The amount, based on thesolids content of the dual-cure mixture of the invention, is preferablyfrom 10 to 80, more preferably from 15 to 75, with particular preferencefrom 20 to 70, with very particular preference from 25 to 65, and inparticular from 30 to 60% by weight.

The dual-cure mixture of the invention further comprises at least oneblocked or unblocked polyisocyanate (B) which includes at least onesoft, flexibilizing segment, which, as a constituent or building blockof three-dimensional polymeric networks, lowers their glass transitiontemperature Tg.

The soft, flexibilizing segments are divalent organic radicals.

Examples of suitable soft, flexibilizing, divalent organic radicals aresubstituted or unsubstituted, preferably unsubstituted, linear orbranched, preferably linear, alkanediyl radicals having from 4 to 30,preferably from 5 to 20 and in particular 6 carbon atoms, which withinthe carbon chain may also contain cyclic groups.

Examples of highly suitable linear alkanediyl radicals aretetramethylene, pentamethylene, hexamethylene, heptamethylene,octamethylene, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl,dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl,penta-decane-1,15-diyl, hexadecane-1,16-diyl, heptadecane-1,17-diyl,octadecane-1,18-diyl, nonadecane-1,19-diyl or eicosane-1,20-diyl,preferably tetramethylene, pentamethylene, hexamethylene,heptamethylene, octamethylene, nonane-1,9-diyl, decane-1,10-diyl,especially hexamethylene.

Examples of highly suitable alkanediyl radicals which also containcyclic groups in the carbon chain are2-heptyl-1-pentylcyclohexane-3,4-bis(non-9-yl), cyclohexane-1,2-, -1,4-or -1,3-bis(methyl), cyclohexane-1,2-, -1,4- or -1,3-bis(eth-2-yl),cyclohexane-1,3-bis(prop-3-yl) or cyclohexane-1,2-, -1,4- or-1,3-bis(but-4-yl).

Further examples of suitable divalent organic radicals are divalentpolyester radicals comprising repeating polyester units of the formula—(—CO—(CHR¹)_(m)—CH₂—O—)—. In this formula the index m is preferablyfrom 4 to 6 and the substituent R¹ is hydrogen or an alkyl, cycloalkylor alkoxy radical. No one substituent contains more than 12 carbonatoms.

Further examples of suitable divalent organic radicals are divalentlinear polyether radicals, preferably having a number average molecularweight of from 400 to 5 000, in particular from 400 to 3 000. Highlysuitable polyether radicals have the general formula—(—O—(CHR²)_(o)—)_(p)O—, where the substituent R² is hydrogen or alower, unsubstituted or substituted alkyl radical, the index o is from 2to 6, preferably from 3 to 4, and the index p is from 2 to 100,preferably from 5 to 50. Especially suitable examples are linear orbranched polyether radicals derived from poly(oxyethylene) glycols,poly(oxypropylene)glycols and poly(oxybutylene)glycols.

Also suitable, furthermore, are linear divalent siloxane radicals, aspresent, for example, in silicone rubbers; hydrogenated polybutadiene orpolyisoprene radicals, random or alternating butadiene-isoprenecopolymer radicals or butadiene-isoprene graft copolymer radicals, whichmay also contain styrene in copolymerized form, and alsoethylene-propylene-diene radicals.

Suitable substituents include all organic functional groups that aresubstantially inert, i.e., which do not undergo reactions withconstituents of the novel dual-cure mixtures.

Examples of suitable inert organic radicals are alkyl groups, especiallymethyl groups, halogen atoms, nitro groups, nitrile groups or alkoxygroups.

Of the above-described divalent organic radicals, the alkanediylradicals containing no cyclic groups in the carbon chain are ofadvantage and are therefore used with preference.

In the blocked or unblocked polyisocyanates (B) it is possible for onlyone kind of the above-described soft, flexibilizing, divalent organicradicals to be present. However, it is also possible to use at least twodifferent divalent organic radicals.

Examples of highly suitable polyisocyanates (B) also suitable forpreparing the blocked polyisocyanates (B) are acylic aliphaticdiisocyanates such as trimethylene diisocyanate, tetramethylenediisocyanate, penta-methylene diisocyanate, hexamethylene diisocyanate,heptamethylene diisocyanate, ethylethylene diisocyanate, trimethylhexanediisocyanate or acyclic aliphatic diisocyanates containing cyclic groupsin their carbon chain, such as diisocyanates derived from difatty acids,as sold under the commercial designation DDI 1410 from Henkel anddescribed in the patents WO 97/49745 and WO 97/49747, especially2-heptyl-3,4-bis(9-isocyanatononyl)-1-pentylcyclohexane, or 1,2-, 1,4-or 1,3-bis(isocyanatomethyl)cyclohexane, 1,2-, 1,4- or1,3-bis(2-isocyanatoeth-1-yl)cyclohexane,1,3-bis(3-isocyanatoprop-1-yl)cyclohexane or 1,2-, 1,4- or1,3-bis(4-isocyanatobut-1-yl)cyclohexane. In the context of the presentinvention, owing to their two isocyanate groups attached exclusively toalkyl groups and despite their cyclic groups, the latter are includedamong the acylic aliphatic diisocyanates.

Of these acyclic aliphatic diisocyanates (B), particular advantage ispossessed by those containing no cyclic groups in their carbon chain. Ofthese, in turn, hexamethylene diisocyanate is especially advantageousand is therefore used with very particular preference.

Further examples of suitable polyisocyanates (B) also suitable forpreparing blocked polyisocyanates (B) are the oligomers of theaforementioned diisocyanates, especially of hexamethylene diisocyanate,that contain isocyanurate, urea, urethane, biuret, uretdione,iminooxadiazinedione, carbodiimide and/or allophanate groups. Examplesof suitable preparation processes are known from the patents CA2,163,591 A, U.S. Pat. No. 4,419,513 A, U.S. Pat. No. 4,454,317 A, EP 0646 608 A, U.S. Pat. No. 4,801,675 A, EP 0 183 976 A1, DE 40 15 155 A1,EP 0 303 150 A1, EP 0 496 208 A1, EP 0 524 500 A1, EP 0 566 037 A1, U.S.Pat. No. 5,258 482 A1, U.S. Pat. No. 5,290,902 A1, EP 0 649 806 A1, DE42 29 183 A1 and EP 0 531 820 A1 or are described in the German patentapplication DE 100 05 228.2, unpublished at the priority date of thepresent specification.

Also suitable are the highly viscous polyisocyanates (B) as described inthe German patent application DE 198 28 935 A1, or the polyisocyanateparticles surface-deactivated by urea formation and/or blocking, as perthe European patent applications EP 0 922 720 A1, EP 1 013 690 A1 and EP1 029 879 A1.

Additionally suitable as polyisocyanates (B) are the adducts, describedin the German patent application DE 196 09 617 A1, of polyisocyanateswith dioxanes, dioxolanes and oxazolidines which containisocyanate-reactive functional groups and still contain free isocyanategroups.

Examples of suitable blocking agents for preparing the blockedpolyisocyanates (B) are the blocking agents from the U.S. patent U.S.Pat. No. 4,444,954 A or U.S. Pat. No. 5,972,189 A, such as

-   i) phenols such as phenol, cresol, xylenol, nitrophenol,    chlorophenol, ethylphenol, t-butylphenol, hydroxybenzoic acid,    esters of this acid, or 2,5-di-tert-butyl-4-hydroxytoluene;-   ii) lactams, such as ε-caprolactam, δ-valerolactam, γ-butyrolactam    or β-propiolactam;-   iii) alcohols such as methanol, ethanol, n-propanol, isopropanol,    n-butanol, isobutanol, t-butanol, n-amyl alcohol, t-amyl alcohol,    lauryl alcohol, ethylene glycol monomethyl ether, ethylene glycol    monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol    monobutyl ether, diethylene glycol monomethyl ether, diethylene    glycol monoethyl ether, diethylene glycol monopropyl ether,    diethylene glycol monobutyl ether, propylene glycol monomethyl    ether, methoxymethanol, 2-(hydroxyethoxy)phenol,    2-(hydroxypropoxy)phenol, glycolic acid, glycolic esters, lactic    acid, lactic esters, methylolurea, methylolmelamine, diacetone    alcohol, ethylenechlorohydrin, ethylenebromohydrin,    1,3-dichloro-2-propanol, 1,4-cyclohexyldimethanol or    acetocyanohydrin;-   iv) mercaptans such as butyl mercaptan, hexyl mercaptan, t-butyl    mercaptan, t-dodecyl mercaptan, 2-mercaptobenzothiazole, thiophenol,    methylthiophenol or ethylthiophenol;-   v) acid amides such as acetoanilide, acetoanisidinamide, acrylamide,    methacrylamide, acetamide, stearamide or benzamide;-   vi) imides such as succinimide, phthalimide or maleimide;-   vii) amines such as diphenylamine, phenylnaphthylamine, xylidine,    N-phenylxylidine, carbazole, aniline, naphthylamine, butylamine,    dibutylamine or butylphenylamine;-   viii) imidazoles such as imidazole or 2-ethylimidazole;-   ix) ureas such as urea, thiourea, ethyleneurea, ethylenethiourea or    1,3-diphenylurea;-   x) carbamates such as phenyl N-phenylcarbamate or 2-oxazolidone;-   xi) imines such as ethyleneimine;-   xii) oximes such as acetone oxime, formaldoxime, acetaldoxime,    acetoxime, methyl ethyl ketoxime, diisobutyl ketoxime, diacetyl    monoxime, benzophenone oxime or chlorohexanone oximes;-   xiii) salts of sulfurous acids such as sodium bisulfite or potassium    bisulfite;-   xiv) hydroxamic esters such as benzyl methacrylohydroxamate (BMH) or    allyl methacrylohydroxamate; or-   xv) substituted pyrazoles, ketoximes, imidazoles or triazoles; and    also    -   xvi) mixtures of these blocking agents, especially        dimethylpyrazole and triazoles, dimethylpyrazole and        succinimide, or butyl diglycol and trimethylolpropane.

The amount of blocked and/or unblocked polyisocyanates (B) in thedual-cure mixtures of the invention may vary widely and is guided inparticular by the functionality of the binder mixtures (A) in respect ofthermal curing, i.e., the number of isocyanate-reactive functionalgroups they contain. The skilled worker is therefore able in eachindividual case to determine the optimum amount with ease on the basisof his or her general knowledge in the art, with the aid if desired ofsimple preliminary experiments. Preferably, the amount of blocked and/orunblocked polyisocyanates (B), based in each case on the solids of thedual-cure mixture of the invention, is from 10 to 70, more preferablyfrom 15 to 65, with particular preference from 20 to 60, with veryparticular preference from 25 to 55, and in particular from 30 to 50% byweight.

Furthermore, the dual-cure mixture of the invention comprises at leastone unsaturated polyfunctional urethane (C).

The unsaturated polyfunctional urethane (C) is free fromisocyanate-reactive functional groups. It contains on average permolecule more than four, preferably at least five, in particular six,carbon-carbon double bonds activatable with actinic radiation. Itfurther comprises at least one hardening segment as a building block ofthe molecule. As a constituent of three-dimensional polymeric networks,the hardening segment increases their glass transition temperature Tg.

The term “polyfunctional” indicates that the urethane (C) contains atleast two urethane groups.

Following their activation with actinic radiation, the carbon-carbondouble bonds bring about the dimerization, oligomerization orpolymerization of the olefinically unsaturated groups in question.

Highly suitable carbon-carbon double bonds are present, for example, in(meth)acryloyl, ethacryloyl, crotonate, cinnamate, vinyl ether, vinylester, ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl,isopropenyl, allyl or butenyl groups; ethenylarylene ether,dicyclopentadienyl ether, norbornenyl ether, isoprenyl ether,isopropenyl ether, allyl ether or butenyl ether groups; orethenylarylene ester, dicyclopentadienyl ester, norbornenyl ester,isoprenyl ester, isopropenyl ester, allyl ester or butenyl ester groups.Of these, (meth)acryloyl groups, especially acryloyl groups, are ofparticular advantage, and so are used with very particular preference inaccordance with the invention.

Accordingly, the polyfunctional unsaturated urethane (C) used withpreference in accordance with the invention comprises a urethane(meth)acrylate.

The hardening segments are divalent or higher multivalent organicradicals. It is preferred to use divalent organic radicals. Alongsidethese in minor amounts it is possible to use multivalent, especiallytrivalent, organic radicals, by means of which it is possible toinfluence the crosslinking density.

Examples of highly suitable hardening segments are divalent aromatic,cycloaliphatic and aromatic-cycloaliphatic radicals, in the case ofwhich within the polyfunctional unsaturated urethane (C), at least onelinking bond leads directly to the cycloaliphatic and/or aromaticstructural unit. Preferably, both linking bonds lead to these structuralunits.

The divalent cycloaliphatic and aromatic radicals, especially thecycloaliphatic radicals, are advantageous and are used with preference.

Examples of suitable divalent aromatic radicals are substituted,especially methyl-substituted, or unsubstituted aromatic radicals havingfrom 6 to 30 carbon atoms in the molecule, such as phen-1,4-, -1,3- or-1,2-ylene, naphth-1,4-, -1,3-, -1,2-, -1,5- or -2,5-ylene,propane-2,2-di(phen-4′-yl), methanedi(phen-4′-yl), diphenyl-4,4′-diyl or2,4- or 2,6-tolylene.

Examples of suitable divalent cycloaliphatic radicals are substituted orunsubstituted, preferably unsubstituted, cycloalkanediyl radicals havingfrom 4 to 20 carbon atoms, such as cyclobutane-1,3-diyl,cyclopentane-1,3-diyl, cyclohexane-1,3- or -1,4-diyl,cycloheptane-1,4-diyl, norbornane-1,4-diyl, adamantane-1,5-diyl,decalindiyl, 3,3,5-trimethylcyclohexane-1,5-diyl,1-methylcyclohexane-2,6-diyl, dicyclohexylmethane-4,4′-diyl,1,1′-dicyclohexane-4,4′-diyl or 1,4-dicyclohexylhexane-4,4″-diyl,especially 3,3,5-trimethylcyclohexane-1,5-diyl ordicyclohexylmethane-4,4′-diyl. Besides these, it is possible in minoramounts to employ the corresponding triyl radicals.

Examples of suitable substituents are those described above.

In principle, the unsaturated polyfunctional urethanes (C) arepreparable by reacting a diisocyanate or polyisocyanate with a chainextender from the group of the diols/polyols and/or diamines/polyaminesand/or dithiols/polythiols and/or alkanolamines and then reacting theremaining free isocyanate groups with at least one compound containingat least one, especially one, of the above-described isocyanate-reactivegroups, especially hydroxyl groups, and also at least one, especiallyone, carbon-carbon double bond.

Highly suitable double bonds are present in the olefinically unsaturatedgroups described above. Of these, (meth)acryloyl groups, especiallyacryloyl groups, are of particular advantage, and so are used with veryparticular preference in accordance with the invention.

Highly suitable compounds for introducing carbon-carbon double bonds arethe monomers (a1) and (a2) described above, especially acrylic acid andmethacrylic acid.

The hardening segments may be introduced both by way of thediisocyanates or polyisocyanates and also by way of the chain extenders.

Highly suitable diisocyanates and polyisocyanates are aromatic andcycloaliphatic, especially cycloaliphatic, diisocyanates andpolyisocyanates. Diisocyanates and polyisocyanates considered aromaticand cycloaliphatic are those in which at least one isocyanate group isattached directly to an aromatic or cycloaliphatic structural unit.

Examples of suitable cycloaliphatic diisocyanates or polyisocyanates forintroducing the hardening segments are isophorone diisocyanate(=5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane),5-isocyanato-1-(2-isocyanatoeth-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-1-(3-isocyanatoprop-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-(4-isocyanatobut-1-yl)-1,3,3-trimethylcyclohexane,1-isocyanato-2-(3-isocyanatoprop-1-yl)cyclohexane,1-isocyanato-2-(3-isocyanatoeth-1-yl)cyclohexane,1-isocyanato-2-(4-isocyanatobut-1-yl)cyclohexane,1,2-diisocyanatocyclobutane, 1,3-diisocyanatocyclobutane,1,2-diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane,1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane,1,4-diisocyanatocyclohexane, dicyclohexylmethane 2,4′-diisocyanate ordicyclohexylmethane 4,4′-diisocyanate, especially isophoronediisocyanate, and also the oligomers of these diisocyanates, especiallyof isophorone diisocyanate, that contain isocyanurate, urea, urethane,biuret, uretdione, iminooxadiazinedione, carbodiimide and/or allophanategroups.

Examples of suitable aromatic diisocyanates and polyisocyanates are 2,4-and 2,6-tolylene diisocyanate, 1,2-, 1,3- or 1,4-phenylene diisocyanate,naphthalene 1,4-, 1,3-, 1,2-, 1,5- or 2,5-diisocyanate,propane-2,2-di(phenyl 4′-diisocyanate), methanedi(phenyl 4′-isocyanates)or 1,1′-diphenyl-4,4′-diisocyanate.

Examples of suitable chain extenders for introducing hardening segmentsare cyclobutane-1,3-diol, cyclopentane-1,3-diol, cyclohexane-1,3- or-1,4-diol, cycloheptane-1,4-diol, norbornane-1,4-diol,adamantane-1,5-diol, decalindiol, 3,3,5-trimethylcyclohexane-1,5-diol,1-methylcyclohexane-2,6-diol, dicyclohexylmethane-4,4′-diol,1,1′-dicyclohexane-4,4′-diol or 1,4-dicyclohexylhexane-4,4″-diol,especially 3,3,5-trimethylcyclohexane-1,5-diol ordicyclohexylmethane-4,4′-diol.

Preferably, the hardening segments are incorporated into the unsaturatedpolyfunctional urethanes (C) by way of the diisocyanates andpolyisocyanates.

Examples of suitable chain extenders which contain no hardening segmentsare described in the German patent application DE 199 14 896 A1, in theGerman patent application DE 44 21 823 A1, page 7 line 65 to page 8lines 2 to 45, and page 10 lines 42 to 48, or in the European patentapplication EP 0 089 497, page 8 line 17 to page 9 line 1.

The amounts of chain extenders, di- and polyisocyanates and compoundscontaining on average at least one isocyanate-reactive group and atleast one carbon-carbon double bond, especially hydroxyalkyl(meth)acrylates, are preferably chosen so that

-   1. the equivalents ratio of the NCO groups to the    isocyanate-reactive groups of the chain extender is between 3:1 and    1:2, and is preferably 2:1, and-   2. the isocyanate-reactive groups of the compounds containing on    average per molecule at least one isocyanate-reactive group and at    least one carbon-carbon double bond, especially hydroxyalkyl    (meth)acrylates, are present in a stoichiometric amount in relation    to the remaining free isocyanate groups of the prepolymer formed    from isocyanate and chain extender.

A further possibility is to prepare the unsaturated polyfunctionalurethanes (C) by first reacting some of the isocyanate groups of a di-or polyisocyanate with at least one compound containing at least oneisocyanate-reactive group and at least one carbon-carbon double bond inthe molecule, especially a hydroxyalkyl (meth)acrylate, and thenreacting the remaining isocyanate groups with a chain extender. In thiscase too, the amounts of chain extender, isocyanate and compound arechosen so that the equivalents ratio of the NCO groups to theisocyanate-reactive groups of the chain extender is between 3:1 and 1:2,and is preferably 2:1, and the equivalents ratio of the remaining NCOgroups to the isocyanate-reactive groups of the compound is 1:1. Ofcourse, all forms lying between these two processes are also possible.For example, some of the isocyanate groups of a diisocyanate may firstbe reacted with a diol as chain extender, after which a further portionof the isocyanate groups may be reacted with the compound, especiallythe hydroxyalkyl (meth)acrylate, and subsequently the remainingisocyanate groups may be reacted with a diamine as chain extender.

These various preparation processes for the urethane (meth)acrylates (C)used inventively with preference are known, for example, from theEuropean patent application EP 0 204 161 A1. The urethane(meth)acrylates (C) are commercially customary compounds and are sold,for example, under the brand name Ebecryl® 1290 by UCB, Belgium.

The amount of the unsaturated polyfunctional urethanes (C) in the noveldual-cure mixtures may vary widely and is guided by the requirements ofthe case in hand, in particular by the crosslinking density to beestablished in the seals, adhesive films and coatings of the inventionthat are produced from the novel dual-cure mixtures. The amount, basedin each case on the solids of the novel dual-cure mixture, is preferablyfrom 5 to 50, more preferably from 8 to 45, with particular preferencefrom 10 to 40, with very particular preference from 12 to 35, and inparticular from 14 to 30% by weight.

The novel dual-cure mixtures may further comprise at least one additive(D), depending on their intended use.

For example, where they are to be used as pigmented coating materials,especially surfacers, solid-color topcoats or basecoats, they maycomprise color and/or effect pigments, electrically conductive pigments,magnetically shielding pigments and/or fluorescent pigments, metalpowders, organic dyes or fillers (D). The pigments may be organic orinorganic in nature.

Examples of suitable effect pigments are metal flake pigments such ascommercially customary aluminum bronzes, aluminum bronzes chromated inaccordance with DE 36 36 183 A1, and commercially customary stainlesssteel bronzes, and also nonmetallic effect pigments, such as pearlescentpigments and interference pigments, platelet-shaped effect pigmentsbased on iron oxide with a shade from pink to brownish red, orliquid-crystalline effect pigments, for example. For further. details,attention is drawn to Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, 1998, page 176, “Effect pigments”, and pages 380 and 381, “Metaloxidemica pigments” to “Metal pigments”, and to the patent applicationsand patents DE 36 36 156 A1, DE 37 18 446 A1, DE 37 19 804 A1, DE 39 30601 A1, EP 0 068 311 A1, EP 0 264 843 A1, EP 0 265 820 A1, EP 0 283 852A1, EP 0 293 746 A1, EP 0 417 567 A1, U.S. Pat. No. 4,828,826 A and U.S.Pat. No. 5,244,649 A.

Examples of suitable inorganic color pigments are white pigments such astitanium dioxide, zinc white, zinc sulfide or lithophones; blackpigments such as carbon black, iron manganese black or spinel black;chromatic pigments such as chromium oxide, chromium oxide hydrate green,cobalt green or ultramarine green, cobalt blue, ultramarine blue ormanganese blue, ultramarine violet or cobalt violet or manganese violet,red iron oxide, cadmium sulfoselenide, molybdate red or ultramarine red;brown iron oxide, mixed brown, spinel phases and corundum phases orchrome orange; or yellow iron oxide, nickel titanium yellow, chrometitanium yellow, cadmium sulfide, cadmium zinc sulfide, chrome yellow orbismuth vanadate.

Examples of suitable organic color pigments are monoazo pigments, disazopigments, anthraquinone pigments, benzimidazole pigments, quinacridonepigments, quinophthalone pigments, diketopyrrolopyrrole pigments,dioxazine pigments, indanthrone pigments, isoindoline pigments,isoindolinone pigments, azomethine pigments, thioindigo pigments, metalcomplex pigments, perinone pigments, perylene pigments, phthalocyaninepigments or aniline black.

For further details, attention is drawn to Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, 1998, pages 180 and 181, “Iron bluepigments” to “Black iron oxide”, pages 451 to 453, “Pigments” to“Pigment volume concentration”, page 563, “Thioindigo pigments”, page567, “Titanium dioxide pigments”, pages 400 and 467, “Naturallyoccurring pigments”, page 459, “Polycyclic pigments”, page 52,“Azomethine pigments”, “Azo pigments”, and page 379, “Metal complexpigments”.

Examples of fluorescent pigments (daylight-fluorescent pigments) arebis(azomethine)pigments.

Examples of suitable electrically conductive pigments are titaniumdioxide/tin oxide pigments.

Examples of magnetically shielding pigments are pigments based on ironoxides or chromium dioxide.

Examples of suitable metal powders are powders of metals and metalalloys, such as aluminum, zinc, copper, bronze or brass.

Suitable organic dyes are lightfast organic dyes having little or notendency to migrate from the novel dual-cure mixtures and the productsproduced from them. The migration tendency may be estimated by theskilled worker on the basis of his or her general knowledge in the artand/or with the aid of simple preliminary rangefinding tests, as part oftinting experiments, for example.

Examples of suitable organic and inorganic fillers are chalk, calciumsulfates, barium sulfate, silicates such as talc, mica or kaolin,silicas, oxides such as aluminum hydroxide, magnesium hydroxide ororganic fillers such as polymer powders, especially those of polyamideor polyacrylonitrile. For further details, attention is drawn to RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, pages 250 ff.,“Fillers”.

It is of advantage to use mixtures of platelet-shaped inorganic fillerssuch as talc, mica and non-platelet-shaped inorganic fillers such aschalk, dolomite, calcium sulfates, or barium sulfate, since by thismeans the viscosity and rheology may be adjusted very effectively.

Examples of suitable transparent fillers are those based on silicondioxide, aluminum oxide or zirconium oxide, but especially nanoparticleson this basis. These transparent fillers may also be present in theunpigmented coating materials of the invention, such as clearcoatmaterials.

Additives (D) which may be present both in pigmented and in theunpigmented novel coating materials are

-   -   additional crosslinking agents, such as amino resins, as        described for example in Römpp Lexikon Lacke und Druckfarben,        Georg Thieme Verlag, 1998, page 29, “Amino resins”, in the        textbook “Lackadditive” [Additives for coatings] by Johan        Bieleman, Wiley-VCH, Weinheim, N.Y., 1998, pages 242 ff., in the        book “Paints, Coatings and Solvents”, second, completely revised        edition, edited by D. Stoye and W. Freitag, Wiley-VCH, Weinheim,        N.Y., 1998, pages 80 ff., in the patents U.S. Pat. No. 4,710,542        A or EP 0 245 700 A1, and also in the article by B. Singh and        coworkers, “Carbamylmethylated Melamines, Novel Crosslinkers for        the Coatings Industry”, in Advanced Organic Coatings Science and        Technology Series, 1991, Volume 13, pages 193 to 207;        carboxyl-containing compounds or resins, as described for        example in the patent DE 196 52 813 A1, compounds or resins        containing epoxide groups, as described for example in the        patents EP 0 299 420 A1, DE 22 14 650 B1, DE 27 49 576 B1, U.S.        Pat. No. 4,091,048 A or U.S. Pat. No. 3,781,379 A; blocked and        unblocked polyisocyanates other than the blocked and unblocked        polyisocyanates (B) and/or tris(alkoxycarbonylamino)triazines,        as known from the patents U.S. Pat. No. 4,939,213 A, U.S. Pat.        No. 5,084,541 A, U.S. Pat. No. 5,288,865 A or EP 0 604 922 A;    -   other radiation-curable constituents, such as        (meth)acryloyl-functional (meth)acrylic copolymers, polyether        acrylates, polyester acrylates, unsaturated polyesters, epoxy        acrylates, urethane acrylates other than the unsaturated        polyfunctional urethanes (C), amino acrylates, melamine        acrylates, silicone acrylates and the corresponding        methacrylates;    -   additional customary and known binders other than the        (meth)acrylate copolymers (A1) and (A2) for use in accordance        with the invention, such as oligomeric and polymeric, thermally        curable, linear and/or branched and/or block, comb and/or random        poly(meth)acrylates or acrylic copolymers, especially those        described in the patent DE 197 36 535 A1; polyesters; those        described in the patents DE 40 09 858 A1 or DE 44 37 535 A1,        alkyds, acrylated polyesters; polylactones; polycarbonates;        polyethers; epoxy resin-amine adducts; (meth)acrylatediols;        partially saponified polyvinyl esters; polyurethanes and        acrylated polyurethanes, especially those described in the        patent applications EP 0 521 928 A1, EP 0 522 420 A1, EP 0 522        419 A1, EP 0 730 613 A1 or DE 44 37 535 A1; or polyureas;    -   typical coatings additives, such as thermally curable reactive        diluents (cf. the German patent applications DE 198 09 643 A1,        DE 198 40 605 A1 or DE 198 05 421 A1) or reactive diluents        curable with actinic radiation (cf. Römpp Lexikon Lacke und        Druckfarben, Stuttgart, N.Y., 1998, page 491), low-boiling        organic solvents and/or high-boiling organic solvents (“long        solvents”), UV absorbers, light stabilizers, free-radical        scavengers, thermolabile free-radical initiators,        photoinitiators, crosslinking catalysts, devolatilizers, slip        additives, polymerization inhibitors, defoamers, emulsifiers,        wetting agents, adhesion promoters, leveling agents, film        formation auxiliaries, rheology control additives, sag control        agents (cf. the patent applications DE 199 24 172 A1, DE 199 24        171 A, EP 0 192 304 A1, DE 23 59 923 A1, DE 18 05 693 A1, WO        94/22968, DE 27 51 761 C1, WO 97/12945 or “farbe+lack”, November        1992, pages 829 ff.); or flame retardants; further examples of        suitable coatings additives are described in the textbook        “Lackadditive” by Johan Bieleman, Wiley-VCH, Weinheim, N.Y.,        1998.

The above-described additives (D) may also be present in the dual-cureadhesives and sealing compounds of the invention, provided they aresuitable for these end uses, which is something that the skilled workermay readily ascertain on the basis of his or her general knowledge inthe art.

The preparation of the dual-cure mixtures of the invention has nospecial features but instead takes place in a customary and known mannerby mixing of the above-described constituents in suitable mixingequipment, such as stirred vessels, dissolvers, stirred mills, staticmixers, toothed-wheel dispersers or extruders, in accordance with thetechniques suitable for preparing the respective dual-cure mixtures,preferably in the absence of actinic radiation.

Depending on their intended use, the dual-cure mixtures of the inventionmay be present as dispersions and/or solutions in organic solvents or inthe form of a substantially or completely solvent-free mixture. Thesubstantially or complete solvent-free mixture may be present in liquidforms (100% system) or powder form. Preferably, the dual-cure mixturesof the invention are present as dispersions and/or solutions in organicsolvents.

The novel dual-cure powder slurries are outstandingly suitable as, or toprepare, dual-cure coating materials, adhesives and sealing compounds.The novel dual-cure coating materials are outstandingly suitable for theproduction of single-coat or multicoat, color and/or effect,electrically conductive, magnetically shielding or fluorescent coatings,such as primer-surfacer coats, basecoats, or solid-color topcoats or ofsingle-coat or multicoat clearcoats. The dual-cure adhesives of theinvention are outstandingly suitable for producing adhesive films, andthe dual-cure sealing compounds of the invention are outstandinglysuitable for producing seals.

Very particular advantages result when the novel dual-cure mixtures areused as clearcoat materials for producing single-coat or multicoatclearcoats. In particular, the novel dual-cure clearcoat materials areused to produce multicoat color and/or effect coating systems by thewet-on-wet technique, in which a basecoat material, especially anaqueous basecoat material, is applied to the surface of the substrate,after which the resulting basecoat film is dried, without being cured,and is overcoated with a clearcoat film. Subsequently, the two films arecured together.

In terms of method, the application of the novel dual-cure coatingmaterials, adhesives and sealing compounds has no special features, butmay instead take place by any customary application method, such asspraying, knifecoating, brushing, flow coating, dipping, trickling orrolling, for example. In the case of the dual-cure coating materials ofthe invention it is preferred to employ spray application methods, suchas compressed air spraying, airless spraying, high-speed rotation,electrostatic spray application (ESTA), alone or in conjunction with hotspray applications such as hot air spraying, for example. Preferably,application takes place in the absence of daylight, in order to preventpremature crosslinking of the novel dual-cure mixtures.

Suitable substrates are all those whose surface is undamaged by theconjoint use of actinic radiation and heat for curing the dual-curefilms present thereon. The substrates preferably consist of metals,plastics, wood, ceramic, stone, textile, fiber composites, leather,glass, glass fibers, glass wool and rockwool, mineral-bound andresin-bound building materials, such as plasterboard and cement slabs orroof tiles, and composites of these materials.

Accordingly, the novel dual-cure coating materials, adhesives andsealing compounds are not only outstandingly suitable for applicationsin the fields of automotive OEM finishing and automotive refinish, butare also suitable for the coating, bonding and sealing of buildings,inside and out, and of doors, windows and furniture, for industrialcoating, including coil coating, container coating and the impregnationand/or coating of electrical components, and also for the coating ofwhite goods, including domestic appliances, boilers and radiators. Inthe context of industrial coatings, they are suitable for coating,bonding or sealing of virtually all parts and articles for private orindustrial use, such as domestic appliances, small metal parts such asnuts and bolts, hubcaps, wheel rims, packaging, or electricalcomponents, such as motor windings or transformer windings.

In the case of electrically conductive substrates, it is possible to useprimers which are prepared in a customary and known manner fromelectrodeposition coating materials. Both anodic and cathodicelectrodeposition coating materials are suitable for this purpose, butespecially cathodic electrodeposition coating materials.Nonfunctionalized and/or nonpolar plastics surfaces may be subjectedprior to coating in a known manner to a pretreatment, such as with aplasma or by flaming, or provided with a water-based primer.

The curing of the applied dual-cure mixtures of the invention also hasno special features in terms of its method but instead takes place inaccordance with the customary and known thermal methods, such as heatingin a forced air oven or irradiation using IR lamps.

Suitable radiation sources for curing with actinic radiation are sourcessuch as high or low pressure mercury vapor lamps, with or without leaddoping in order to open up a radiation window of up to 405 nm, orelectron beam sources. Further examples of suitable processes andequipment for curing with actinic radiation are described in the Germanpatent application DE 198 18 735 A1, column 10 lines 31 to 61.

The resulting novel coatings, especially the single-coat or multicoatcolor and/or effect coatings and clearcoats of the invention, are easyto produce and have outstanding optical properties and very high lightstability, chemical resistance, water resistance and weatheringstability. In particular, they are free from clouding andinhomogeneities. Moreover, they are hard, flexible and scratchresistant. They possess outstanding intercoat basecoat/clearcoatadhesion and good to very good adhesion to customary and knownautomotive refinishes and to automotive production-line repair finishes.As is known, in the case of automotive production-line repair finishing,the ready-painted bodies are coated once again with the OEM finishes.

The adhesive films of the invention connect a very wide variety ofsubstrates to one another firmly and durably and have a high chemicaland mechanical stability even under extreme temperatures and/ortemperature fluctuations.

Similarly, the seals of the invention provide durable sealing of thesubstrates, and exhibit high mechanical and chemical stability evenunder extreme temperatures and/or temperature fluctuations, and even inconjunction with exposure to aggressive chemicals.

Accordingly, the primed or unprimed substrates commonly employed in thetechnological fields recited above and coated with at least one novelcoating, bonded with at least one novel adhesive film and/or sealed withat least one novel seal combine a particularly advantageous profile ofperformance properties with a particularly long service life, whichmakes them particularly attractive economically.

EXAMPLES Preparation Example 1

The Preparation of a Methacrylate Copolymer (A1)

A suitable laboratory reactor equipped with stirrer, reflux condenserand two feed vessels was charged with 48 parts by weight ofSolventnaphtha® and this initial charge was heated to 160° Celsius.Subsequently, from the first feed vessel, a monomer mixture of 44.5parts by weight of ethylhexyl acrylate, 10 parts by weight of styrene,27 parts by weight of hydroxyethyl methacrylate and 15 parts by weightof 4-hydroxybutyl acrylate and 3.5 parts by weight of acrylic acid wasmetered in over the course of four hours, and from the second feedvessel a solution of 8.0 parts by weight of tert-butylperoxyethylhexanoate and 6 parts by weight of Solventnaphtha® wasmetered in over the course of four and a half hours, both feeds takingplace at a uniform rate and with stirring. The feeds were commencedsimultaneously. After the end of the second feed (initiator feed), thereaction mixture was polymerized at 160° C. for two hours more. Thisgave a solution of the methacrylate copolymer (A1) having a solidscontent of 60.4% by weight (one hour/130° C.) with an acid number of24.3 mg KOH/g solids and a hydroxyl number of 175 mg KOH/g solids. Themethacrylate copolymer (A1) had a glass transition temperature, Tg, of−22° C.

Preparation Example 2

The Preparation of a Methacrylate Copolymer (A2)

Preparation example 1 was repeated except that 61 parts by weight ofSolventnaphtha® were used as the initial charge and the initiator feedadded was a solution of 4.5 parts by weight of tert-butylperoxyethylhexanoate and 6 parts by weight of Solventnaptha® and themonomer feed used was a monomer mixture of 10 parts by weight ofstyrene, 31.5 parts by weight of tert-butyl acrylate, 15 parts by weightof n-butyl methacrylate, 40 parts by weight of hydroxypropylmethacrylate and 3.5 parts by weight of acrylic acid. This gave asolution of the methacrylate copolymer (A2) having a solids content of58.6% by weight (one hour/130° C.) with an acid number of 27.5 mg KOH/gsolids and a hydroxyl number of 156 mg KOH/g solids. The methacrylatecopolymer (A2) had a glass transition temperature, Tg, of +65° C.

Example 1

The Preparation of an Inventive Dual-cure Clearcoat Material

The inventive dual-cure clearcoat material-was prepared by mixing andhomogenizing the following constituents:

-   -   53.1 parts by weight of the solution of the methacrylate        copolymer (A1) from preparation example 1,    -   61.4 parts by weight of the solution of the methacrylate        copolymer (A2) from preparation example 2,    -   70.8 parts by weight of an 80% strength solution in methyl ethyl        ketone of a 2,5-dimethylpyrazole-blocked        hexamethylenediisocyanate,    -   31.8 parts by weight of an aliphatic urethane acrylate based on        isophorone diisocyanate and containing 6 acrylate groups in the        molecule (Ebecryl® 1290 from UCB, Belgium),    -   1.27 parts by weight of a photoinitiator mixture comprising        Irgacure® 184 and Irgacure® 819 in a ratio of 7:1,    -   1.5 parts by weight of a light stabilizer (Tinuvin® 400, UV        absorber from Ciba Specialty Chemicals), and    -   1.5 parts by weight of a reversible free-radical scavenger based        on a sterically hindered amine (HALS) (Tinuvin® 292 from Ciba        Specialty Chemicals).

The inventive dual-cure clearcoat material was stable on storage and intransit.

Example 2

The Production of a Multicoat Color and/or Effect Coating System with anInventive Clearcoat

To produce the multicoat system, steel test panels which have beencoated with an electrocoat in a dry film thickness of from 18 to 22 μmwere coated with a water-based primer-surfacer. The resultingprimer-surfacer film was baked at 160° C. for 20 minutes to give aprimer-surfacer coat with a dry film thickness of from 35 to 40 μm. Theprimer-surfacer coat was subsequently coated with an aqueous basecoatmaterial from BASF Coatings AG (MB 9040) in a film thickness of from 12to 15 μm. The resultant aqueous basecoat films were flashed off at 80°C. for 10 minutes. Thereafter the clearcoat material of example 1 wasapplied pneumatically using a gravity-feed gun in one cross pass in afilm thickness of from 40 to 45 μm. Subsequently, the clearcoat filmswere flashed off at room temperature for 10 minutes and at 80° C. for 10minutes. The flashed-off clearcoat films were cured first with UVradiation (dose: 1 500 mJ/cm²; belt speed 4 m/min). Subsequently, theaqueous basecoat films and the clearcoat films were cured thermally in aforced air oven at 155° C. for 30 minutes.

The chemical resistance was determined with the aid of the MB gradientoven test, known in the art, following aging of the multicoat systems atroom temperature for 72 hours. In this test, marking first occurred at51° C. for 1% strength sulfuric acid, at 48° C. for pancreatin, at 61°C. for tree resin, and not until more than 72° C. for deionized water.

The inventive multicoat system had a gloss to DIN 67530 of 90.

The scratch resistance was determined with the aid of the Amtec test,which is known in the art, following aging of the inventive multicoatsystems at room temperature for seven days. The result was a decrease inthe degree of gloss (20°) of 22.7.

The micropenetration hardness was determined separately on an inventiveclearcoat. It was 181 N/mm² (universal hardness at 25.6 mN, Fischerscope100 V with Vickers diamond pyramid).

The maximum of the loss factor tan δ and the storage modulus E′ of theclearcoat material and, respectively, of the clearcoat were determinedwith the aid of the DMTA method, as described in detail in the Germanpatent DE 197 09 467 C1, in the article by Th. Frey, K.-H,Groβe-Brinkhaus, U. Röckrath, Cure Monitoring of Thermoset Coatings,Progress In Organic Coatings, Volume 27 (1996), pages 59 to 66, or inthe German patent application DE 44 09 715 A1. The maximum of the lossfactor tan δ was at 86° C., and the storage modulus E′ was 4.8×10⁷ Pa,i.e., within the plastic range.

The test results underline the outstanding visual properties, the highchemical and water resistance, the high flexibility and hardness, andthe very good scratch resistance of the inventive clearcoats.

Preparation Example 3

The Preparation of a Methacrylate Copolymer for Use in a ThixotropicPaste

A laboratory reactor with a capacity of 4 l, equipped with a stirrer,two dropping funnels for the monomer mixture and initiator solutionrespectively, a nitrogen inlet pipe, a thermometer and a refluxcondenser, was charged with 720 g of an aromatic hydrocarbon fractionhaving a boiling range of 158–172° C. The solvent was heated to 140° C.After it had reached 140° C., a monomer mixture of 450 g of 2-ethylhexylmethacrylate, 180 g of n-butyl methacrylate, 210 g of styrene, 180 g ofhydroxyethyl acrylate, 450 g of 4-hydroxybutyl acrylate and 30 g ofacrylic acid was metered into the reactor at a uniform rate over thecourse of 4 hours, and an initiator solution of 150 g of t-butylperethylhexanoate in 90 g of the above-described aromatic solvent wasmetered into the reactor at a uniform rate over the course of 4.5 hours.The additions of the monomer mixture and of the initiator solution werecommenced simultaneously. After the end of the initiator feed, thereaction mixture was held at 140° C. for two hours more and then cooled.The resulting polymer solution had a solids content of 65%, determinedin a forced air oven at 130° C. for 1 h, an acid number of 15, and aviscosity of 3 dPas (measured on a 60% dilution of the polymer solutionin the above-described aromatic solvent, using an ICI cone-and-plateviscometer at 23° C.).

Preparation Example 4

The Preparation of a Thixotroping Paste

A stirred laboratory mill from Vollrath was charged with 800 g ofmillbase consisting of 323.2 g of the methacrylate copolymer frompreparation example 3, 187.2 g of butanol, 200.8 g of xylene and 88.8 gof Aerosil® 812 (Degussa AG, Hanau), together with 1 100 g of quartzsand (particle size 0.7–1 mm) and this millbase was dispersed for 30minutes with water cooling. Subsequently, the quartz sand was separatedoff.

Examples 3 to 8

The Preparation of Inventive Two-component Dual-cure Clearcoat Materials

Example 3

The clearcoat material from example 3 was prepared by mixing andhomogenizing the following constituents:

Stock Coating:

-   -   28.04 parts by weight of the methacrylate copolymer (A1) from        preparation example 1,    -   16.87 parts by weight of the methacrylate copolymer (A2) from        preparation example 2,    -   20 parts by weight of an aliphatic urethane acrylate based on an        isophorone diisocyanate containing 6 acrylate groups in the        molecule (Ebecryl® 1290 from UCB, Belgium),    -   2.13 parts by weight a tris(alkoxy-carbonylamino)triazine (TACT®        from CYTEC; 50% strength solution in butanol),    -   2.13 parts by weight of the thixotroping paste from preparation        example 4,    -   14.44 parts by weight of sag control agent (Setalux® 81753 from        Akzo; urea content 1.3% by weight),    -   1.14 parts by weight of a UV absorber (Cyagard® 1164L;        substituted hydroxyphenyltriazine, 65% strength in xylene),    -   0.76 part by weight of a reversible free-radical scavenger        (Tinuvin® 292; sterically hindered amine (HALS)),    -   2.13 parts by weight of Dibasic Ester® from Du Pont (mixture of        dialkyl esters of succinic acid, glutaric acid and adipic acid),    -   0.1 part by weight of a conductivity additive (Byk® ES 80),    -   0.8 part by weight of a dispersant (Disperbyk® 161),    -   0.16 part by weight of a leveling agent (Byk®310),    -   5.2 parts by weight of butyldiglycol acetate,    -   4.8 parts by weight of methoxypropyl acetate (technical-grade        mixture), and    -   1.3 parts by weight of butyl acetate

Crosslinking Agent:

-   -   90% dilution of the trimer of the isocyanurate type of        hexamethylene diisocyanate in solvent naphtha/butyl acetate 1:1        (Desmodur® N 3390 from Bayer AG).

The ratio of stock coating to crosslinking agent was 100:33.

Example 4

Example 3 was repeated but using

-   -   44.91 parts by weight of the methacrylate copolymer (A1) from        preparation example 1        instead of 28.04 parts by weight of the methacrylate copolymer        (A1) from preparation example 1 and 16.87 parts by weight of the        methacrylate copolymer (A2) from preparation example 2.

Example 5

Example 3 was repeated but using

-   -   54.8 parts by weight of Desmodur® N 3390,    -   35.2 parts by weight of the trimer of the isocyanate type of        isophorone diisocyanate (Desmodur® Z4470, 70% strength, from        Bayer AG) and    -   10 parts by weight of butyl acetate        as crosslinking agent instead of Desmodur® N 3390. The ratio of        stock coating to crosslinking agent was 100:39.5.

Example 6

Example 5 was repeated but using

-   -   44.91 parts by weight of the methacrylate copolymer (A1) from        preparation example 1        instead of 28.04 parts by weight of the methacrylate copolymer        (A1) from preparation example 1 and 16.87 parts by weight of the        methacrylate copolymer (A2) from preparation example 2.

Example 7

Example 3 was repeated but using

-   -   23 parts by weight of Desmodur® N 3390    -   64 parts by weight of Desmodur® Z4470,    -   6.5 parts of by weight of butyl acetate and    -   6.5 parts by weight of Solventnaphtha®        instead of Desmodur® N3390 alone. The ratio of stock coating to        crosslinking agent was 100:50.

Example 8

Example 7 was repeated but using

-   -   44.91 parts by weight of the methacrylate copolymer (A1) from        preparation example 1        instead of 28.04 parts by weight of the methacrylate copolymer        (A1) from preparation example 1 and 16.87 parts by weight of the        methacrylate copolymer (A2) from preparation example 2.

The clearcoat materials of examples 3 to 8 had a long processing timeand could be applied without problems.

Examples 9 to 14

The Production of Multicoat Color and/or Effect Coating Systems withInventive Clearcoats of the Invention

For example 9, the clearcoat material from example 3 was used.

For example 10, the clearcoat material from example 4 was used.

For example 11, the clearcoat material from example 5 was used.

For example 12, the clearcoat material from example 6 was used.

For example 13, the clearcoat material from example 7 was used.

For example 14, the clearcoat material from example 8 was used.

For the coatings tests, multicoat systems were produced on steel testpanels. These panels had been coated with an electrocoat in a dry filmthickness of from 18 to 22 μm. The test panels were first of all coatedwith a water-based primer-surfacer. The resulting primer-surfacer filmwas baked at 160° C. for 20 minutes to give a primer-surfacer coathaving a dry film thickness of from 35 to 40 μm. The primer-surfacercoat was subsequently coated with an aqueous basecoat material from BASFCoatings AG (MB 9040) in a film thickness of from 12 to 15 μm. Theresulting aqueous basecoat films were flashed off at 80° C. for 10minutes. Thereafter the clearcoat materials of examples 3 to 8 wereapplied vertically by an electrostatic method (bell type: Eccobell) in asingle application, each in a film thickness of from 40 to 45 μm. Theclearcoat films were subsequently flashed off at room temperature for 10minutes and at 80° C. for 10 minutes. The flashed-off clearcoat filmswere cured first with UV radiation (dose: 1 500 mJ/cm²; belt speed 4m/min). Thereafter, the aqueous basecoat films and the clearcoat filmswere thermally cured in a forced air oven at 130° C. for 22 minutes.

To measure the micropenetration hardness, clearcoats were producedseparately on steel panels (cf. example 2). In order to simulate theircuring behavior in shadow zones of substrates, one series of test panelswas cured only thermally.

The scratch resistance was determined using the Amtec test, brush testand sand test, these tests being known in the art. The gloss wasdetermined in accordance with DIN 67530 before and after exposure.

The chemical resistance was determined with the aid of the MB gradientoven test, which is known in the art, after aging of the multicoatsystems at room temperature for 72 hours. The temperatures reported arethose at which damage to the clearcoats first became evident.

The intercoat adhesion (basecoat/clearcoat) was determined using thecross-cut test.

In addition, one series of test panels was sanded and overcoated with acustomary and known multicoat automotive refinish. The adhesion betweenoriginal finish and refinish was again determined using the cross-cuttest.

Additionally, one series of test panels was recoated with the aqueousbasecoat material and overcoated with the respective clearcoat materialof examples 3 to 8, in order to simulate the production-line repaircoating of a motor vehicle in the unsanded state. Subsequently, theproduction-line repair coating films were cured under the sameconditions as for the original finishes (multicoat systems of examples 9to 14). The adhesion was again determined using the cross-cut test.

The cross-cut test was conducted as described in Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, N.Y., 1998, page 263,“Cross-cut test”.

The results of the investigations can be found in table 1.

TABLE 1 Results of the coatings tests on the multicoat systems andclearcoats of examples 9 to 14 Examples: Test Remark 9 10 11 12 13 14Amtec Initial gloss 89 89 88 86 85 88 Gloss without 36 47 36 35 26 36wiping Gloss with 71 60 68 59 51 54 wiping delta gloss 18 29 20 27 34 34with wiping Brush Initial gloss 89 89 88 86 85 88 test Gloss after 67 6860 57 52 62 exposure Gloss after 70 73 63 59 56 64 2 h/40° C. Glossafter 79 73 63 61 58 69 2 h/60° C. delta gloss: Brush test 22 21 28 2933 26 2 h/40° C. 19 16 25 27 29 24 2 h/60° C. 10 8 23 25 27 19 Sand testInitial gloss 89 89 88 86 85 88 Gloss after 67 68 65 63 59 65 exposureGloss after 68 69 66 63 60 65 2 h/40° C. Gloss after 72 74 69 64 60 67 2h/60° C. delta gloss: Sand test 22 21 22 22 26 23 2 h/40° C. 21 20 22 2226 23 2 h/60° C. 17 15 18 21 25 21 Chemical Sulfuric acid 47 51 57 54 5753 resistance Pancreatin <36 <36 <37 <36 42 <36 (° C.) Tree resin >6259 >62 60 >62 50 Distilled >62 >62 >62 >62 >62 >62 water Micropene-Curing: tration Without UV 109.2 83.9 109.2 83.9 145.9 112.3 hardness UVand 153.7 143.1 172.1 175.1 181.7 168.5 (N/mm2) thermally AdhesionIntercoat 0.5 0.5 0.5 1.5 1 0.5 (GT) Production- 0.5 0.5 0.5 2.5 5 0.5line repair coating Automotive 0.5 0.5 0.5 0.5 0.5 0.5 refinish

The results show the high level of hardness of the clearcoat of theinvention, even in the shadow zones, the high chemical resistance andwater resistance, the high scratch resistance and the very good adhesionof the clearcoats of the invention. Furthermore, the results show thatthe profile of properties of the clearcoat materials of the inventionmay be varied widely by way of their material composition and adaptedoutstandingly to the respective end use.

1. A mixture curable thermally and with actinic radiation comprising (A)a binder free from carbon-carbon double bonds activatable with actinicradiation comprising at least one (meth)acrylate copolymer containing onaverage per molecule at least one isocyanate-reactive functional groupand having a glass transition temperature Tg of from −40 to +80° C., (B)at least one polyisocyanate that is at least one of blocked andunblocked having at least one soft, flexibilizing segment, which as aconstituent of three-dimensional polymeric networks lowers their glasstransition temperature Tg, and (C) at least one unsaturatedpolyfunctional urethane that is free from isocyanate-reactive functionalgroups and contains on average per molecule more than four carbon-carbondouble bonds activatable with actinic radiation and at least onehardening segment, the hardening segment as a constituent ofthree-dimensional polymer networks increasing their glass transitiontemperature Tg.
 2. The mixture of claim 1, wherein the binder comprises(A1) at least one (meth)acrylate copolymer containing on average permolecule at least one isocyanate-reactive functional group and having aglass transition temperature Tg below room temperature, and (A2) atleast one (meth)acrylate copolymer containing on average per molecule atleast one isocyanate-reactive functional group and having a glasstransition temperature Tg above room temperature.
 3. The mixture ofclaim 2, wherein the glass transition temperature Tg of the(meth)acrylate copolymer (A1) is below 0° C. and the glass transitiontemperature Tg of the (meth)acrylate copolymer (A2) is above 30° C. 4.The mixture of claim 1, wherein the isocyanate-reactive groups areselected from the group consisting of hydroxyl groups, thiol groups,primary amino groups, secondary amino groups, and combinations thereof.5. The mixture of claim 4, wherein the isocyanate-reactive groups arehydroxyl groups.
 6. The mixture of claim 1, wherein the at least one(meth)acrylate copolymer has a hydroxyl number of from 50 to 300 mgKOH/g.
 7. The mixture of claim 1, wherein the at least one(meth)acrylate copolymer has an acid number of up to 70 nag KOH/g. 8.The mixture of claim 1, wherein the carbon-carbon double bond is presentin at least one of a (meth)acryloyl group, an ethacryloyl group, acrotonate group, a cinnamate group, a vinyl ether group, a vinyl estergroup, an ethenylarylene group, a dicyclopentadienyl group, anorbornenyl group, an isoprenyl group, an isopropenyl group, an allylgroup, a butenyl group, an ethenylarylene ether group, adicyclopentadienyl ether group, a norbornenyl ether group, an isoprenylether group, an isopropenyl ether group, an allyl ether group, a butenylether group, an ethenylarylene ester group, a dicyclopentadienyl estergroup, a norbornenyl ester group, an isoprenyl ester group, anisopropenyl ester group, an allyl ester group, an a butenyl ester group.9. The mixture of claim 8, wherein the carbon-carbon double bonds arepresent in a (meth)acryloyl group.
 10. The mixture of claim 1, whereinthe soft, flexibilizing segment is selected from the group consisting of(i) alkanediyl radicals having from 4 to 20 carbon atoms that areunsubstituted or substituted and are linear or branched; (ii) divalentpolyester radicals comprising repeating polyester units of the formula—(—CO—(CHR¹)_(m)—CH₂—O—)—, in which the index m is from 4 to 6 and thesubstituent R¹ is hydrogen or an alkyl, cycloalkyl or alkoxy radical, noone substituent containing more than 12 carbon atoms; (iii) divalentlinear polyether radicals of the general formula—(—O—(CHR²)_(o)—)_(p)O—, where the substituent R² is hydrogen or alower, unsubstituted or substituted alkyl radical and the index o isfrom 2 to 6, and the index p is from 2 to 100; (iv) linear divalentsiloxane radicals, (v) divalent hydrogenated polybutadiene radicals;(vi) divalent hydrogenated polyisoprene radicals; (vii) divalentradicals of random or alternating butadiene-isoprene copolymers; (viii)divalent radicals of butadiene-isoprene graft copolymers; and (ix)divalent radicals of ethylene-propylene-diane copolymers.
 11. Themixture of claim 1, wherein the hardening segments are selected from thegroup consisting of aromatic radicals and cycloaliphatic radicals thatare at least divalent.
 12. The mixture of claim 11, wherein thehardening segments are selected from the group of the cycloaliphaticradicals.
 13. The mixture of claim 1, wherein the at least onepolyisocyanate comprises linear aliphatic segments.
 14. The mixture ofclaim 13, wherein the at least one polyisocyanate comprising linearaliphatic segments are selected from the group consisting ofhexamethylene diisocyanate and its oligomers.
 15. The mixture of claim1, wherein the at least one unsaturated polyfunctional urethanecomprises a product of polyisocyanates comprising methyl-substitutedcycloaliphatic segments.
 16. The mixture of claim 15, wherein thepolyisocyanates comprising methyl-substituted cycloaliphatic segmentsare selected from the group consisting of isophorone diisocyanate andits oligomers.
 17. The mixture of claim 1, wherein the mixture ispresent in one of a dispersion in an organic solvent, a solution in anorganic solvent or as a solvent-free mixture.
 18. The mixture of claim17, wherein the solvent-free mixture is present in liquid form or powderform.
 19. The mixture of claim 1, wherein the mixture is one of acoating material, an adhesive, or a sealing compound.
 20. The mixture ofclaim 19, wherein the coating material is a clearcoat material.
 21. Amethod comprising applying the mixture of claim 1 to a substrate as oneof an automotive OEM finish, an automotive refinish, a building coating,a furniture coating, a window coating, a door coating, an industrialcoating, a coil coating, a container coating, an impregnation ofelectrical components, an electrical component coating, a white goodscoating, an appliance coating, a boiler coating, and a radiator coating.